• Climate change

• Land transformation

• Disruption of biogeochemical cycles

• Pollution

• Introduction of species outside their native ranges

GHG’s play a critical role in maintaining Earth’s habitable temperature. Without GHG’s, Earth would likely plunge into an ice age, as heat would escape back into space.

• Species distribution shifts

• Migration and breeding changes

• Coral bleaching, ocean acidification

• Extinctions

• Agriculture: Conversion of forests, grasslands, and wetlands into croplands and pastures

• Urbanization: Expansion of cities, roads, and infrastructure fragments natural habitats
  • Increases impervious surfaces, disrupting water flow, urban heat islands, and pollution

• Deforestation: Logging for timber, agriculture, and fuel
  • removes carbon sinks, causes soil erosion, and loss of biodiversity

• Infrastructure Development: Construction of dams, highways, and mining operations
  • modifies/removes habitats, interrupts animal migration routes and river flows.

• Land Drainage: Conversion of wetlands, estuaries, and mangroves for development
  • Loss of ecosystems that buffer storms and filter pollutants.

• Biogeochemical cycle: the movement and transformation of chemical elements/compounds between living organisms, the atmosphere, and the Earth’s crust

• Carbon Cycle - C is main element for building organic molecules essential for life
  • Fossil Fuel Combustion: Releases vast amounts of CO₂
  • Deforestation: Reduces the Earth’s capacity to absorb atmospheric carbon

• Nitrogen Cycle - N is used to build molecules like proteins, nucleic acids (DNA and RNA)
  • Synthetic Fertilizer: Adds nitrogen to soils and waterways, which escapes into aquatic ecosystems
  • Fossil Fuel Combustion: Produces greenhouse gasses, contributes to smog, and acid rain,
  • Livestock Waste: Releases greenhouse gasses

• Phosphorus Cycle - building blocks like DNA and RNA, energy molecules, cell membranes
  • Agricultural Runoff: Excess phosphorus from fertilizers enters rivers and lakes
  • Wastewater Discharge: Human sewage contributes to phosphorus overload in aquatic systems

Excessive nutrient levels lead to rapid algal growth. As these algal blooms decay, oxygen is depleted in the water, suffocating fish and other organisms

Oceans absorb CO₂. When CO₂ dissolves in seawater, it forms carbonic acid, releasing hydrogen ions and increases ocean acidity. More acidification makes it harder for organisms to build/maintain shells

• Industrial Activities (factories) emit air pollutants
  • Chemical waste and heavy metals often contaminate soil and water.
  • Plastic manufacturing also contributes to microplastic pollution.

• Vehicles release GHG’s, volatile organic compounds (VOCs), and particulate matter
  • land and air transportation

• Agriculture fertilizer, pesticides and herbicides contaminate soil and water
  • harming non-target organisms

• Residential and Urban Waste includes household chemicals, plastic, and electronic waste
  • dssege and wastewater discharge pollutes aquatic ecosystems

• Plastic waste, oil spills, and ballast water discharge pollute oceans and harm marine life

• An introduced species is a species that has been brough by human activity to an area where it does not naturally occur

Invasive species often lack natural predators/diseases in new locations, allowing them to grow rapidly and outcome native species